Letters archive

You reported on future houses that claim an impressively low day-to-day energy use. However, it is important to remember that, as we progressively reduce this form of energy use, we ignore embodied energy – that required to create the building – at our peril( 25 February, p 11 ). In homes of the sort described, …

I enjoyed your look at AI theory of mind (ToM), related research and the promise of smarter AI assistants as a result of this work( 18 February, p 46 ). However, I can't help feeling that something isn't quite right about where this is heading. As one of the researchers says, an AI ToM won't …

According to your guide to being your own hero, psychologists say we should spin our memories "into a well-told life narrative" to "help us achieve our aspirations for self-improvement". Why always this pressure to perform better, because that is what it comes down to (which isn't the same as saying that unhealthy behaviour shouldn't be …

The Hoover dam had a maximum power output of 2080 megawatts before river flows declined ( 4 March, p 27 ).

This article reminded me of the emotional attachments of a local cat. When we moved to our house, it lived in our garden and our neighbour's. Its owner had moved about 6 kilometres away. She had taken the cat and kept it indoors for a few weeks because cats have a reputation of returning to …

I'm sure I won't be alone in congratulating you on taking the science of cat "ownership" seriously. Regarding the test on whether your cat can read your gaze, our cat Bertie understands the concept of following human gaze. He has long requested food close to mealtimes from people near his food bowl in the kitchen …

You wonder if affection in cats is, in fact, cupboard love. When I go out, my cat waits for hours by my front door, with much vocalisation and rubbing when I return, but it's not for food. There is untouched food in her bowl. She also sleeps beside me on the couch with one paw …

On the subject of the 2000-watt energy-saving challenge, we consume energy at the rate of 12,000 kilowatts per year to run our house of five people and charge an electric car( 11 February, p 36 ). This equates to a rate of energy use of 1400 watts an hour. We have no gas, just a …

"Messages from the Stone Age", about hand stencils found in caves and early human culture, brings to mind 16,500-year-old cave paintings in Lascaux, France. These are said to show the constellation Taurus as a bull with the Hyades star cluster as the face and, above it, the Pleiades, as well as other stars. Such art …

Your story claims that mongooses and warthogs provide the only example of mutualism between two mammal species. Hang on, what about dogs and humans? We provide food and a warm place to sleep. They help us hunt, herd our sheep, protect our property, guide those who are blind, offer comfort, give older people a reason …